• Journal of Nutrition and Health
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• 제33권4호
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• pp.365-373
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• 2000

The purpose of this study was to compare the nutritional effects of resistant starch, cellulose and pectin on growth rate, metabolic energy and apparent digestibility in rats. Forty eight male Sprague-Dawley rats were randomly assigned to six dietary treatments, Rats were fed, ad libitum one of six experimental diets: 5% of resistant starch (RS), 5% of cellulose (CE), 5% of pection(PT), 2.5% resistant starch and 2.5% cellulose(RS+CE), 2.5% resistant starch and 2.5% pectin(RS+PT), and 2.5% cellulose and 2.5% pectin (CE+PT) during 4 weeks. The results obtained were as follows: body weight gain were higher in groups RS and CE, compared with that in the group PT, where other groups such as RS+CE, RS+PT and CE+PT showed no significant differences to the RS group. Food intake and food efficiency into showed the same patterns. Metabolic energy were similar in the RS and CE, and was the lowest the metabolic energy in the group CE+PT was significantly low. Apparent digestibility of protein was significantly higher in the group RS, compared with the groups CE and PT. Apparent digestibility of mixed dietary fiber groups such as the RS+CE, RS+PT and CE+PT group were also higher compared with the group PT. Apparent digestibility of lipid were significantly higher in the groups RS, CE and PT. Apparent digestibility of lipid in the mixed pectin groups such as the RS+PT and CE+PT growth rate, metabolic energy and apparent digestibility of lipid in the mixed pectin groups such as the RS+PT and CE+PT recorded the lowest, while that of the group RS+CE was significantly high. From above results, following was concluded: The growth rate, metabolic energy and apparent digestibility of protein and lipid of group RS were significantly higher in comparision with the group PT, while availability of energy nutrients of group CE was similar to that of the group RS. Also resistant starch fed with pectin(RS+PT) seemed to have increased the growth rate and the apparent digestibility of protein compared with those of the group PT fed with pectin(PT) alone, however RS+PT scemed to have the apparent digestibility of lipid.

• Proceedings of the Korea Concrete Institute Conference
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.947-952
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• 2001

The prediction model is proposed to estimate the variation of compressive strength of fly ash concrete with aging. After analyzing the experimental result with the model, the regression results are presented according to fly ash replacement content and water/cement ratio. Based on the regression results, the influence of fly ash replacement content and water/cement ratio on apparent activation energy was investigated. According to the analysis, the model provides a good estimate of compressive strength development of fly ash concrete with aging. As the fly ash replacement content increases, the limiting relative compressive strength and initial apparent activation energy become greater. The concrete with water/cement ratio smaller than 0.40 shows that the limiting relative compressive strength and apparent activation energy are nearly constant according to water/cement ratio. But, the concrete with water/cement ratio greater than 0.40 has the increasing limiting relative compressive strength and apparent activation energy with increasing water/cement ratio.

• Journal of the Korea Concrete Institute
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• 제12권2호
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• pp.31-42
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• 2000

This paper discusses the validity of models predicting the compressive strength of concrete subjected to various temperature histories and the shortcomings of existing rate constant model and apparent activation energy concept. Based on the discussion, a modified rate constant model is proposed. The modified rate constant model, in which apparent activation energy is a nonlinear function of curing temperature and age, accurately estimates the development of the experimental compressive strengths by a few researchers. Also, the apparent activation energy of concrete cured with high temperature decreases rapidly with age, but that of concrete cured with low temperature decreases gradually with age. Finally generalized models to predict apparent activation energy and compressive strength are proposed, which are based on the regression results.

• Journal of Powder Materials
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• 제20권5호
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• pp.332-337
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• 2013

Recently, self-propagating high-temperature synthesis (SHS), related to metallic and ceramic powder interactions, has attracted huge interest from more and more researchers, because it can provide an attractive, energy-efficient approach to the synthesis of simple and complex materials. The adiabatic temperature $T_{ad}$ and apparent activation energy analysis of different thermit systems plays an important role in thermodynamic studies on combustion synthesis. After establishing and verifying a mathematic calculation program for predicting adiabatic temperatures, based on the thermodynamic theory of combustion synthesis systems, the adiabatic temperatures of the NiO/Al aluminothermic system during self-propagating high-temperature synthesis were investigated. The effect of a diluting agent additive fraction on combustion velocity was studied. According to the simulation and experimental results, the apparent activation energy was estimated using the Arrhenius diagram of $ln(v/T_{ad}){\sim}/T_{ad}$ based on the combustion equation given by Merzhanov et al. When the temperature exceeds the boiling point of aluminum (2,790 K), the apparent activation energy of the NiO/Al aluminothermic system is $64{\pm}14$ kJ/mol. In contrast, below 2,790 K, the apparent activation energy is $189{\pm}15$ kJ/mol. The process of combustion contributed to the mass-transference of aluminum reactant of the burning compacts. The reliability of the simulation results was experimentally verified.

• Proceedings of the Korea Concrete Institute Conference
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• 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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• pp.155-158
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• 1999

This paper discusses the validity of models to predict the compressive strength of concrete subjected to various temperature histories and the shortcomings of existing rate constant model and apparent activation energy concept. Based on the discussion, a modified rate constant model is proposed. The modified rate constant model, in which apparent activation energy is a nonlinear function of curing temperature and age, accurately estimates the development of the experimental compressive strengths by a few researches. Also, the apparent activation energy of concrete cured with high temperature decreases rapidly with age, but that cured with low temperature decreases gradually with age. Finally a generalized model to predict apparent activation energy and compressive strength is proposed, which is based on the regression results.

• Proceedings of the Korean Institute of Building Construction Conference
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• 한국건축시공학회 2021년도 봄 학술논문 발표대회
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• pp.78-79
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• 2021

It is necessary to calculate Apparent Activation Energy(Ea) in order to apply the equivalent age formula to predict compressive strength using the maturity method. For carbon reduction, it is necessary to consider the change of Ea by condition of GGBFS concrete, which is widely used today. In this study, as a basic study for the design of the compressive strength model of GGBFS concrete, the apparent activation energy of the GGBFS mixed paste was calculated through a calorimeter. The experiment was carried out at a hydration temperature of 10 to 30℃ with a paste test specimen having a GGBFS content of 0 to 80%. As a result, the GGBFS replacement rate of the paste increased, and Ea tended to increase as the temperature decreased.

• Proceedings of the Korean Institute of Building Construction Conference
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.101-102
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• 2021

The compressive strength of concrete is greatly affected by the temperature inside the concrete at the initial age immediately after pouring. The apparent activation energy of cement and the setting time of concrete are major factors influencing the development of compressive strength of concrete. This study measured the apparent activation energy and setting time according to the change in W/B for each mixing rate of Ground Granulated Blast-Furnace Slag (GGBFS). And after calculating the compressive strength prediction model, the accuracy of the prediction model was evaluated by comparing the predicted compressive strength and the compressive strength.

• Korean Journal of Poultry Science
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• 제21권2호
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• pp.133-138
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• 1994

A study of concurrent bioassay for protein quality and energy level in protein sources was rnade by determining urinary nitrogenous compounds in excreta. The carry over effect of previous feeding was eliminated by 48 h of feeding the experimental diets prior to the determination of for protein digestibility and utilizability, and energy digestibility and metabolizability at 24 h interval during 3 days. Then, protein qualities and energy levels for soybean meal, rapeseed meal and fish meal were calculated by a substitution method. Apparent protein utilization (NB/NI) was affected by the increased fecal nitrogen excretion in soybean meal and by the increased urinary nitrogen excretion in rapeseed meal and fish meal. The apparent metabolizability of energy (ME/GE) was affected by the fecal energy excretion in soybean meal and rapeseed meal and by urinary energy excretion in fishmeal. The results indicated that the concurrent bioassay of protein quality and energy levels in ingredients appears to be applicable to chickens of other age, sex, breeds and environmental conditions.

• Journal of the Korea Concrete Institute
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• 제13권3호
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• pp.237-243
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• 2001

The prediction model is proposed to estimate the variation of compressive strength of fly ash concrete with aging. After analyzing the experimental result with the model, the regression results are presented according to fly ash replacement content and water-cement ratio. Based on the regression results, the influence of fly ash replacement content and water-cement ratio on apparent activation energy was investigated. According to the analysis, the model provides a good estimate of compressive strength development of fly ash concrete with aging. As the fly ash replacement content increases, the limiting relative compressive strength and initial apparent activation energy become greater. The concrete with water-cement ratio smaller than 0.40 shows that the limiting relative compressive strength and apparent activation energy are nearly constant according to water-cement ratio. But, the concrete with water-cement ratio greater than 0.40 has the increasing limiting relative compressive strength and apparent activation energy with increasing water-cement ratio.

• Journal of Aquaculture
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• 제21권2호
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• pp.89-95
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• 2008

Flounder were fed a reference diet and test diets containing various feed ingredients: mackerel fish meal, meat meal, soybean meal, wheat flour, wheat gluten, corn gluten meal and brewer's yeast. Apparent digestibility was determined using a reference diet with 0.5% chromic oxide indicator and test diets contained 70% reference diet and 30% of the feed ingredient being evaluated. Apparent digestibility coefficients for amino acid and energy in the reference and test diets were determined, and digestibility coefficients for the test ingredients were calculated based on differences in the digestibility of test diets relative to the reference diet. The fish averaging 300 g were held in 2000 L tanks at a density of 20 fish per tank. Feces were collected from three replicate groups of fish using a fecal collection column attached to fish rearing tank. Apparent total amino acids digestibilities(90-95%) of mackerel fish meal, soybean meal, wheat gluten, corn gluten meal and brewer's yeast were higher than those of meat meal and wheat flour(P<0.05). Apparent energy digestibilities(86-98%) of mackerel fish meal, meat meal, soybean meal, wheat gluten and corn gluten meal were significantly higher(P<0.05) than those of wheat flour and brewer's yeast. These results provide useful information about nutrient and energy utilization for flounder.